2.9.4 Typesetting Gregorian chant

When typesetting a piece in Gregorian chant notation, the
Vaticana_ligature_engraver automatically selects the
proper note heads, so there is no need to explicitly set the note
head style. Still, the note head style can be set, e.g., to
vaticana_punctum to produce punctum neumes. Similarly, the
Mensural_ligature_engraver automatically assembles
mensural ligatures.

Gregorian chant contexts

The predefined VaticanaVoiceContext and
VaticanaStaffContext can be used to engrave a piece of
Gregorian chant in the style of the Editio Vaticana. These contexts
initialize all relevant context properties and grob properties to
proper values, so you can immediately go ahead entering the chant, as
the following excerpt demonstrates:

Gregorian clefs

The following table shows all Gregorian clefs that are supported via
the \clef command. Some of the clefs use the same glyph,
but differ only with respect to the line they are printed on. In
such cases, a trailing number in the name is used to enumerate
these clefs, numbered from the lowest to the highest line. Still,
you can manually force a clef glyph to be typeset on an arbitrary
line, as described in 音部記号. The note printed to the right
side of each clef in the example column denotes the c' with
respect to that clef.

Divisiones

There are no rests in Gregorian chant notation; instead, it uses
Divisiones.

A divisio (plural: divisiones; Latin word for
‘division’) is a staff context symbol that is used to indicate
the phrase and section structure of Gregorian music. The musical
meaning of divisio minima, divisio maior, and
divisio maxima can be characterized as short, medium, and
long pause, somewhat like the breath marks from ブレス記号.
The finalis sign not only marks the end of a chant, but is
also frequently used within a single antiphonal/responsorial chant
to mark the end of each section.

To use divisiones, include the file ‘gregorian.ly’. It
contains definitions that you can apply by just inserting
\divisioMinima, \divisioMaior, \divisioMaxima,
and \finalis at proper places in the input. Some editions use
virgula or caesura instead of divisio minima.
Therefore, ‘gregorian.ly’ also defines \virgula and
\caesura

Augmentum dots (morae)

Augmentum dots, also called morae, are added with the music
function \augmentum. Note that \augmentum is
implemented as a unary music function rather than as head prefix. It
applies to the immediately following music expression only. That is,
\augmentum \virga c will have no visible effect. Instead, say
\virga \augmentum c or \augmentum {\virga c}. Also
note that you can say \augmentum {a g} as a shortcut for
\augmentum a \augmentum g.

Gregorian square neume ligatures

There is limited support for Gregorian square neumes notation
(following the style of the Editio Vaticana). Core ligatures can
already be typeset, but essential issues for serious typesetting are
still lacking, such as (among others) horizontal alignment of multiple
ligatures, lyrics alignment, and proper handling of accidentals.

The support for Gregorian neumes is enabled by \includeing
‘gregorian.ly’ at the beginning of the file. This makes available
a number of extra commands to produce the neume symbols used in
plainchant notation.

Note heads can be modified and/or joined.

The shape of
the note head can be modified by prefixing the note name
with any of the following commands:
\virga,
\stropha,
\inclinatum,
\auctum,
\descendens,
\ascendens,
\oriscus,
\quilisma,
\deminutum,
\cavum,
\linea.

Ligatures, properly speaking (i.e. notes joined together), are
produced by placing one of the joining commands \pes or
\flexa, for upwards and downwards movement, respectively,
between the notes to be joined.

A note name without any qualifiers will produce a punctum.
All other neumes, including the single-note neumes with a
different shape such as the virga, are in principle
considered as ligatures and should therefore be placed
between \[…\].

Single-note neumes:

The punctum is the basic note shape (in the
Vaticana style: a square with some curvation for
typographical finesse). In addition to the regular
punctum, there is also the oblique punctum
inclinatum, produced with the prefix \inclinatum. The
regular punctum can be modified with \cavum, which
produces a hollow note, and \linea, which draws vertical
lines on either side of the note.

The virga has a descending stem on the right side. It is
produced by the modifier \virga.

Ligatures

Unlike most other neumes notation systems, the typographical
appearance of ligatures is not directly dictated by the input
commands, but follows certain conventions dependent on musical
meaning. For example, a three-note ligature with the musical shape
low-high-low, such as \[ a \pes b \flexa g \], produces a
Torculus consisting of three Punctum heads, while the shape
high-low-high, such as \[ a \flexa g \pes b \], produces a
Porrectus with a curved flexa shape and only a single Punctum
head. There is no command to explicitly typeset the curved flexa
shape; the decision of when to typeset a curved flexa shape is
based on the musical input. The idea of this approach is to
separate the musical aspects of the input from the notation style
of the output. This way, the same input can be reused to typeset
the same music in a different style of Gregorian chant notation.

Liquescent neumes

Another main category of notes in Gregorian chant is the so-called
liquescent neumes. They are used under certain circumstances at
the end of a syllable which ends in a ‘liquescent’ letter, i.e.
the sounding consonants that can hold a tone (the nasals, l, r, v,
j, and their diphthong equivalents). Thus, the liquescent neumes
are never used alone (although some of them can be produced), and
they always fall at the end of a ligature.

Liquescent neumes are represented graphically in two different,
more or less interchangeable ways: with a smaller note or by
‘twisting’ the main note upwards or downwards. The first is
produced by making a regular pes or flexa and
modifying the shape of the second note:
\[ a \pes \deminutum b \] , the second by modifying the shape
of a single-note neume with \auctum and one of the direction
markers \descendens or \ascendens, e.g.,
\[ \auctum \descendens a \] .

Special signs

A third category of signs is made up of a small number of signs
with a special meaning (which, incidentally, in most cases is only
vaguely known): the quilisma, the oriscus, and the
strophicus. These are all produced by prefixing a note name
with the corresponding modifier, \quilisma,
\oriscus, or \stropha.

Virtually, within the ligature delimiters \[ and \],
any number of heads may be accumulated to form a single ligature,
and head prefixes like \pes, \flexa, \virga,
\inclinatum, etc. may be mixed in as desired. The use of
the set of rules that underlies the construction of the ligatures
in the above table is accordingly extrapolated. This way,
infinitely many different ligatures can be created.

Note that the use of these signs in the music itself follows
certain rules, which are not checked by LilyPond. E.g., the
quilisma is always the middle note of an ascending
ligature, and usually falls on a half-tone step, but it is
perfectly possible, although incorrect, to make a single-note
quilisma.

In addition to the note signs, ‘gregorian.ly’ also defines the
commands \versus, \responsum, \ij,
\iij, \IJ, and \IIJ, that will produce the
corresponding characters, e.g., for use in lyrics, as section
markers, etc. These commands use special Unicode characters and
will only work if a font is used which supports them.

The following table shows a limited, but still representative pool
of Gregorian ligatures, together with the code fragments that
produce the ligatures. The table is based on the extended neumes
table of the 2nd volume of the Antiphonale Romanum
(Liber Hymnarius), published 1983 by the monks of Solesmes.
The first column gives the name of the ligature, with the main form in
boldface and the liquescent forms in italics. The third column
shows the code fragment that produces this ligature, using
g, a, and b as example pitches.

参照

既知の問題と警告

When an \augmentum dot appears at the end of the last staff
within a ligature, it is sometimes vertically placed wrong. As a
workaround, add an additional skip note (e.g., s8) as last note
of the staff.

\augmentum should be implemented as a head prefix rather than a
unary music function, such that \augmentum can be intermixed
with head prefixes in arbitrary order.